1. Field of the Invention
The present invention relates to a continuous process for the preparation of alkali metal perchlorates and, more especially, to the preparation of such perchlorates by electrolysis of aqueous solutions of the chlorates of such alkali metals.
Hereinafter, unless otherwise indicated, the chlorate of the alkali metal and the perchlorate of the alkali metal shall be referred to, respectively, as the "chlorate" and the "perchlorate".
2. Description of the Prior Art
The advantage of continuously preparing the alkali metal perchlorates is described, for example, in FR 1,402,590, and in U.S. Pat. Nos. 3,518,173, 3,518,180 and 3,475,301, and BR 125,608.
Such technique entails electrolyzing the chlorate in a succession of individual stages, each being different from and a tributary of another and providing only partial electrolysis relative to the intended final industrial result.
Therefore, to date an aqueous solution of perchlorate has been produced by the electrolysis of the chlorate, such that the perchlorate can be separated directly by crystallization, for example by cooling or by the evaporation of water therefrom.
It is known to this art that the electrolysis of the chlorate in a single stage does not produce such a solution as prepared under the practical conditions described, for example, in U.S. Pat. No. 2,512,973.
Conducting the operation in a large number of individual stages, in contrast is recommended, for example, in U.S. Pat. No. 3,475,301.
In a plural-stage process, commonly designated "in cascade", the total electrolytic equilibrium is disturbed by the electrolytic inbalance of a single stage and cannot be re-established simply by discontinuation of the "defective" stage.